1. Field of the Invention
The invention relates in general to motor vehicle exhaust lines.
More precisely, the invention relates to a motor vehicle exhaust line silencer, of the type comprising:                an upper shell comprising a substantially flat upper end wall;        a lower shell comprising a substantially flat lower end wall parallel to the upper end wall,the upper and lower shells delimiting between them an internal volume of the silencer.        
2. Description of Related Art
Such a silencer is known from JP-2006-283645, which describes a silencer comprising a plurality of internal pipes each rigidly fixed to both the upper end wall and the lower end wall. The pipes thus divide the internal volume of the silencer into a plurality of chambers.
Such a silencer is of low height, in other words there is a small gap between the upper end wall and the lower end wall. Using such a silencer thus allows the vehicle chassis to be lowered, and therefore increases the usable volume of said vehicle. However, for a given internal volume of the silencer, because of its low height said silencer must have a large area, and in particular a high ratio between its length and its width.
For a given internal volume, said silencer generates more noise than a silencer of greater height and smaller area. Moreover, the quantity of raw material, in particular of metal, required to produce said silencer, is greater. The noise generated is due to the vibration of the different parts forming the silencer under the effect of the exhaust gas flow.
In this context, the object of the invention is to propose a silencer of which the construction is suitable for obtaining a low height, a large area and a high length/width ratio, which has good acoustic performance and requires the use of a moderate quantity of raw material.